Mirror clock



Aug. 8, 1939 w. I. KETTERSON 2,169,099

MIRROR CLOCK Filed July 7, 1938 Inventor" Willis 1. Ketter'son,

His Attorney.

Patented Aug. 8,1939 2,169,099

" UNITED STATESPATENT OFFICE MIRROR CLOCK Willis I. Ketterson, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application July 7, 1938, Serial No. 217,899 6 Claims. (Cl. 58-2) My invention relates to a two-faced indicating hands would appear if considered as viewed frominstrument such asa clock, together with reflecta direction in front of the clock. Looking diing mirror means whereby the indication of the rectly at the back face of the clock, the rear minclock or other device may be observed in its proper ute hand will, of course, rotate in a counterclockperspective from various different view points. wise direction. A second back gear 2| between 5 The features of my invention which are believed shaft I6 and a hollow shaft on the rear of shaft to be novel and patentable will be pointed out in i6 drives a rear hour hand 22 in the same directhe claims appended hereto. For abetter undertion as hand 20 but at the lower speed of one standing of my invention, reference is made in the revolution in twelve hours. The visual arrangefoliowing description to the accompanying drawment of the rear clock dial and hands is a reversed l ing in which Fig. 1 represents a two-faced clock image of the front arrangement. It is seen that setting on a table having a mirror back showing the double clock-driving mechanism is very simhow the time may be correctly read from the ple. The two back gears and two sets of hands image of the rear face of the clock; Fig. 2 shows may be duplicates and there is no reversing gear the rear face of the clock represented in Fig. 1; arrangement such as has previouslgbeen used on 1 Fig. 3 represents a plan view of a form of my in'- double-faced clocks intended to be observed from vention where the reflecting mirror is hinged to opposite directions. the rear of the clock casing; Fig. 4 shows a plan In Fig. l the two-faced clock just described is view of a double mirror arrangement and indicatrepresented as setting at an angle on a table 23 ing device arranged for observation from three having a mirror back 24, such that the normal directions, 90 degrees apart; Fig. 5 shows a clock front clock face Il may be read directly from the driving arrangement forthe front and rear sets front and the reflected image of the rear clock of hands; Fig. 6.shows a switchboard measuring face appears in the mirror at 25. In reflecting instrument such as an ammeter to which my inthe rear clock face, the time graduation arrangevention has been' applied; and Fig. 7 shows a ment and the direction of rotation of the hands form of forked indicating pointer that may be thereof are reversed in the image so that the used in the instrument of Fig. 6. image appears as a normal clock face with the Referring principally to Figs. 1, 2 and 5, Hi is pointers in their proper positions and rotating in a clock casing having a usual form of front clock the proper direction and at the proper rates to dial H and hour and minutehands I2 and I3. tell time. Where, as usual, the front direct view The hands are driven from any suitable timing of the clock and the reflected rear image of the motor such as a synchronous electric motor repclock are intended to indicate the same time of resented at H in Fig. 5. In this clock drive, I5 day, the front and rear minute hands will be in represents reduction gearing between the motor alignment and likewise the front and rear hour and minute hand shaft l6. l1 represents the hands will be in alignment, as shown in Fig. 5. usual back gears between the minute hand shaft However, the front clock face may, for example, and a hollow shaft on shaft I for driving indicate daylight saving time and the image the hour hand I2 at the desired rate. These standard time, should that be desired, simply by hands are driven in a clockwise direction in the properly setting the front and. rear clock hands usual manner. accordingly.

The clock is also provided with a dial H in It is now evident that the clock represented, its rear wall on which the time graduation scale when placed in front of a mirror, will indicate time is arranged counterclockwise or reversed, as comcorrectly and can be readily observed from vari pared to the front scale, when this rear face is ous different angles of a room, and that the most directly observed, asshown in Fig. 2. Also, the suitable position of the clock and reflected image numbers on the clock face .are reversed so that for time observation purposes in any particular I a reflected image of such rear clock face will room can be easily arrived at by angular adjustappear as a normal clock face with the numerals 'ments of the clock with respect to the mirror, arranged clockwise and properly oriented. The tilting the clock or mirror, etc. rear dial is also provided with minute and hour In Fig. 3 I have shown a plan view of a clock hands 20-and 22. The minute hand 2| is mounted 26 which will have front and rear clock faces as directly on minute hand shaft II which extends described, with a mirror 21 hinged to the rear through the clock from front to back at right of the clock case, the mirror surface facing toangles to the clock faces and drives both minute wards the back of the clock. This mirror may hands It and 2| ins. clockwise direction as these also serve as a supporting device to help hold the u means cooperating with the clock upright. As adjusted in Fig. 3, the clock is arrangedto tell time to observers looking in the general direction indicated by the two arrows.

In Fig. 4 I have shown a plan view of my double-faced clock ID in combination with two angularly disposed mirrors 28 and 28 at the rear thereof. Time may be conveniently observed by this arrangement from three directions, 90 degrees, more or less apart. The three arrows in this figure point in the directions in which different persons "may look simultaneously to observe the time of day.-

The invention is not confined to clocks but may be applied to other typesof indicating instruments. In Fig. 6 I have represented at II a switchboard ammeter casinghaving a front indicating scale and pointer 34. The instrument is secured to supporting structure 33 to which also a mirror 32 is secured. The mirror and instrument are preferably relatively adjustable in order that the angle between the mirror and rear of the instrument may be varied for best observation purposes. The rear of the provided with a reversed scale and with an indicating pointer opposite the front scale and pointer. The reflected image of the rear of the instrument is shown in the mirror 32.

The two pointers will be operated by the same moving instrument armature so that no expensive departure from usual instrument design practice is required. For example, the double pointer arrangement may take the form shown in Fig. 'I. Here, I have represented at 36 a usual form of armature assembly structure for a magnetic vane ammeter. The front pointer 34 may have a rear extensioh to form the rear pointer indicator What I claim as new and desire to secure by Letters Patent of the United States is:

1. An indicating instrument comprising a casing having front and rear scale graduations arranged opposite each other, movable pointer two scales, common means within said casing for simultaneously moving the indicating means with respect to their scales in the same direction, and mirror means to the rear of said casing for reflecting an image of the rear scale and pointer, said rear scale having its graduations arranged so that when reversed by mirror reflection its image has the same scale arrangement as the front scale. 2. An indicating instrument having a casing, graduated scales on opposite sides of said casing facing to the frontand rear respectively, pointers cooperating with both scales, common means within said casing for simultaneously moving both pointers with respect to their scales, the rear scale and pointer having substantially the appearance of a mirror image of the front scale and pointer and a mirror adjustably positioned with respect to the rear scale and pointer for reflecting an image thereof.

3.1m indicating instrument comprising a casing, graduated scales in the front and rear walls of -casing for rotating said instrument will be said casing and facing the front and rear respectively, a shaft in said casing extending at right angles to said scales, pointers for each of said scales secured to said shaft, means in said shaft, the pointer and scale arrangement at the rear having substantially the appearance of a mirror image of the front scale and pointer arrangement, and a mirror hinged to the rear of said casing to one side of the scale with its mirror surface towards the rear scale and serving rear scale and pointer at an angle.

4. An indicating instrument comprising a casing, front and rear indicating scales in the front and rear walls of said casing, pointers cooperating with each scale, common measurement means within said casing for simultaneously moving said pointers with respect to their scales, the appearance of the rear scale and pointer being substantially that of a mirror image of the front scale and pointer, and a pair of mirrors positioned to the rear of said casing with their mirror surfaces reversely inclined towards the casing so as to reflect images of the rear scale and pointer in opposite directions generally parallel to the rear scale.

5. An indicating instrument comprising a casing having a clock dial in a front wall thereof. a dial in the rear wall of said casing which in appearance is a mirror image of the front clock dial, minute and hour hands cooperating with each dial, a minute hand shaft within said casin extending substantially through said casing from the front to the rear, the minute hands for the front and rear dials being secured to said shaft, a pair of hollowhour hand shafts to which said hour hands are secured on opposite ends of said to reflect an-image of said minute hand shaft, a pair of similar speed reducing gear trains between the minute and hour hand shafts adjacent the opposite ends of the minute hand shaft, a timing motor connected to drive the minute hand shaft at a point between the pair of speedreducing gear trains, and a mirror to ,the rear of said clock casing for reflecting an image of the rear dial and hands in a direction from which the front clock dial can not be observed.

6. An indicating instrument comprising a casing, a clock dial in the front of said casing, time telling hands cooperating with said dial, a clock movement within the casing for rotating said hands at the proper rates to indicate time, a dial may be observed.

WILLIS I. KE'I'TERSON. 

